Larvae Crowding Increases Development Rate, Improves Disease Resistance, and Induces Expression of Antioxidant Enzymes and Heat Shock Proteins in Mythimna separata (Lepidoptera: Noetuidae)
Larvae Crowding Increases Development Rate, Improves Disease Resistance, and Induces Expression of Antioxidant Enzymes and Heat Shock Proteins in Mythimna separata (Lepidoptera: Noetuidae)
复制标题
DOI：
10.1093/jee/toab105
复制
发表时间：
2021-06-09
影响因子：
2.2
通讯作者：
Hu, Yang
中科院分区：
文献类型：
--
作者：
Li, Hongbo;Dai, Changgeng;Hu, Yang
高种群密度（拥挤）成为昆虫的压力因素。东方粘虫Mythimna separata（步行者）在高密度和低密度时分别表现出群居和独居相。本研究比较了两个时期的黑胫病的生活史、抗病性、抗氧化酶和热休克蛋白（HSPs）的诱导。分离幼虫结果表明，群居幼虫比独居幼虫具有更快的生长速度和更低的蛹重。此外，群居的个人表现出较高的生存率比孤独的个人后白僵菌感染。群居幼虫有较高的丙二醛含量相比，孤独的，但总的抗氧化能力没有差异，观察感染前后的两个幼虫阶段。超氧化物歧化酶和谷胱甘肽过氧化物酶的活性在群居型M.在感染前，粘虫幼虫比单虫幼虫的感染率高，但在感染后的两个时期，粘虫幼虫的感染率没有显著差异。而过氧化物酶和过氧化氢酶活性在侵染前和侵染后两个时期均无显著差异。Hsp19.8和Hsp90在群居幼虫中的表达上调时相比，单独的个人之前或之后感染。CuZnSOD的表达在感染前的两个阶段之间没有差异，但在感染后，群居的比独居的上调。然而，在群居幼虫的其他压力相关基因的表达被抑制或不变时，单独的个人相比，感染前或感染后。由此可见，幼虫拥挤改变了生活史，提高了稻瘟病菌的抗病性。separata幼虫，并诱导抗氧化酶和热休克蛋白对真菌感染的可变反应。
High population density (crowding) becomes a stress factor in insects. The oriental armyworm, Mythimna separata (Walker), displays gregarious and solitary phases at high and low population densities, respectively. In this study, we compared life history, disease resistance, and induction of antioxidant enzymes and heat shock protein (HSPs) in two phases of M. separata larvae. Results showed that gregarious larvae had a faster growth rate and lower pupal weight compared to solitary larvae. Furthermore, gregarious individuals exhibited higher survival rates than solitary individuals after Beauveria bassiana infection. The gregarious larvae had higher malondialdehyde content compared to solitary ones, but no differences in total antioxidant capacity were observed between the two larval phases before or after infection. Superoxide dismutase and glutathione peroxidase activities were significantly lower in gregarious M. separata larvae than solitary individuals before infection, but no difference was detected in two phases after infection. However, peroxidase and catalase activities in the two phases showed no difference either before or after infection. Hsp19.8 and Hsp90 expression in gregarious larvae were up-regulated when compared to solitary individuals before or after infection. CuZnSOD expression was not different between the two phases before infection, but it was up-regulated in gregarious ones compared to solitary ones after infection. However, expression of other stress-related genes in gregarious larvae was either repressed or unchanged when compared to solitary individuals before or after infection. Thus, larval crowding changed life history, improved disease resistance of M. separata larvae, and induced variable response of antioxidant enzymes and HSPs to fungal infection.